This invention relates to a golf club, and more particularly to improvements in a club head structure of a wood-type golf club.
Recently, a so-called two-component type golf ball, which has a spherical elastic core covered with an outer plastic cover, has been widely used among golfers.
As is well-known, the two-component type golf ball is generally of less compressibility (elastic-deformability), and therefore has a smaller contact area, upon impact with a golf club face, as compared with the conventional thread-wound type golf ball which includes a known internal layer formed of wound rubber threads. Accordingly, at the moment when the two-component type ball is hit by the front face of the club head of the golf club, the impact force applied to a local surface spot of the club head face is considerably greater than that in the case of the aforesaid conventional thread-wound type golf ball. Thus, use of the two-component type golf ball has required that a certain reinforcement be added in order to maintain the desired durability of the body of the wooden club head of the wood-type golf club, as will be further described hereinbelow.
The wood-type golf club generally has a club head body formed of a hard wood block such as that of persimmon, and in many cases, a reinforcing insert or face plate, made of ABS resin, vulcanized fibre, light alloy or other suitable durable material, is embedded in and permanently attached, by adhesive or other means to an appropriate recess formed in the center of an impact front face of the body of the wooden club head, in such a manner that the external surface of the embedded face plate lies substantially flush with the wooden front surface area adjacent the embedded face plate, as disclosed, for example, in U.S. Pat. No. 4,181,306 to Jepson.
Thus, so long as a golf ball is correctly hit by the golf club on the embedded face plate, no problem arises. In fact, however, golfers, especially beginners, occasionally hit mis-shots such that the ball is not hit on the face plate but on the incorrect wooden front face area adjacent to the reinforcing face plate. This mis-shot, if the two-component type golf ball is used, results in the formation of an undesirable dent or depression in that portion of the wooden front surface of the golf club head which the golf ball hits. And such mis-shots, if repeated, will finally cause the development of cracks in the wooden club head body.
As will be apparent from the above descrption, the use of the two-component type golf ball has brought about an increase in damage to the wooden club head body and therefore a shorter span of life of the wooden-type golf club.
It is, therefore, a principal object of the present invention to substantially reduce the above-discussed problem with respect to the durability of the wooden club head body of the wood-type golf club.
Another object of the invention is to provide an improved golf club head whose wooden club head body is reinforced by a wood-plastic combination so as to provide a sufficient mechanical strength against impact imparted thereto upon hitting of the two-component type golf ball.
A further object of the invention is to provide an improved golf club head whose wooden club head body is reinforced without losing balance in weight.
Still a further object of the invention is to provide an improved golf club head whose wooden club head body is excellent in dimensional stability, waterproofness, painting efficiency, and glossiness, of the finished surface.